Ahhh, love in the 21st century. Now that we're putting off marriage longer than ever and many of us even have kids before marriage, living together is basically the new engaged. But whether it's just a stepping stone or a substitute for "I do," moving inis a big deal.

My BF and I did it a little over 2 years after we first started dating, and for us, that was the perfect timing. For others, it's six months or even six years and having that a marriage certificate in hand might be the ticket. Either way, there are quite a few (silly and serious) must-dos to check off your list before co-habitating with your honey ...

1. At least consider "The 2-Year Rule." A wise friend of mine suggests couples NOT live together until after hitting that milestone. To quote, "All the warm fuzzies are gone and you're left with what's real ... AND can run if need be!"

2. Learn as much as you can about his relationship with his mother. She will become a greater presence in your life once you're living at the same address.

3. Know if one of you is a slob and the other is a neat freak. Figure out how you're going to cope if you are polar opposites.

4. Discuss chores. Will he do the laundry, and you'll do the dishes? Or will you split everything 50/50?

5. Get any hankering for college-era hookups outta your system. You will not be bringing other people back for any hankypanky once you live with your S.O.

6. Throw out your ugliest undies that you wouldn't want him to find.

7. Get rid of old love letters from your exes aka boxes filled with crap you saved from pastrelationships. If you're moving in with the love of your life, you don't need 'em.

8. Make sure he's seen you with acne medicine or your face mask or whatever else you put on your face at 9 p.m. on a Wednesday night.

9. Be comfortable with him seeing you in your rattiest sweatpants, a sweatshirt and/or hair that hasn't been washed in 48 hours.

10. Make sure you know one another's policy on bathroom privacy/closing the door.

11. Be comfortable doing your, err, business with him in the same apartment/house.

12. Be OK with his flatulence and your own in front of him!

13. Make sure he knows and respects the TV shows you can't miss and vice-versa. Be cool with shows like How It's Made and endless episodes of Family Guy.

14. Then, get a DVR. Trust me.

15. Know that if you get sick or end up in the hospital, he takes good care of you.

16. Be ready to take care of him when he gets sick and acts like a big baby.

17. Buy odor-fighting foot spray to have stashed in your new place.

18. Be comfortable eating -- no, really, EATING -- in front of him!

19. Consider if you're in tune religiously (think about if you want a Kosher kitchen, he wants a Christmas tree, yadda yadda).

20. Think about how your morning/nighttime schedules might clash. If they will, figure out a game plan for dealing with this.

21. Have a conversation with your mother in front of him. He should be prepared to know if you morph into a different person when yakking with Mommy Dearest.

22. Be prepared to have him steal your smartphone to play Angry Birds or check FOREX or look at dumb YouTube videos.

23. Know whether or not he snores.

24. Have a plan for dealing with his snoring. (Note: It may only occur seasonally.)

25. Decide together whether or not you're okay with having a TV in the bedroom.

26. Consider whether you need all those shoes/handbags/clothes/makeup. He will say something about how much space they're taking up. Again. And again.

36. Spend a significant amount of time in a confined space together. 4-6 hours in a car on a road trip will do it!

37. If you drink too much and end up throwing up in a space that isn't exactly easy to clean, know that he'll take care of you/it.

38. Have a serious discussion about finances, debts, creditors who call you like they're your BFF.

39. Spend at least one major holiday with one another's families.

40. Have some tricks up your sleeve to deal with his most obnoxious familymembers.

41. Discuss how you both feel about having friends or relatives hanging out at your place or sleeping over.

42. Be on the same page about smoking, drinking, recreational drug use.

43. Tell your family and friends flat-out that you're moving in together. You should have no reason to hide.

44. Be in sync with exercise habits/goals. If you're pounding away to a Jillian Michaels DVD and he is just going to stare at you from the couch while eating Doritos, you may have a problem.

45. Trust him enough to have absolutely no reason to snoop on him once his laptop, Blackberry, wallet, etc. are well within your reach on a daily basis.

46. Be well-versed on one another's health background -- physical and mental.

47. Plan a budget together. Talk about your priorities when it comes to saving/spending.

48. Think about how frequently you want to have sex once you're under the same roof. Now lower your expectations just a smidge. There ya go.

49. Consider how you plan to spend time away from him for the health of your relationship. Girls' nights, Zumba classes, work happy hours all count.

50. Be sure you're definitely going to want to see one another from day 1 to 365 -- after all, you don't want to break up with each other, have to break your lease, and end up losing your security deposit!